UWB-MAC: MAC protocol for UWB localization using ultra-low power anchor nodes

Indoor localization systems allow for innovative Industry 4.0 applications such as tracking of assets, people, or robots. Due to its cm-level accuracy, the Ultra Wide Band (UWB) technology seems to be a perfect fit as an enabler for these advanced use cases. Most current UWB research papers and commercial offerings assume that battery-powered mobile tags communicate with non-energy constrained infrastructure devices. However, in many deployments it is not possible to offer the required power cabling at the correct locations to provide energy to all infrastructure nodes. To this end, this paper proposes a novel power-aware Medium Access Control (MAC) protocol that uses a probed, secondary wake-up radio to maximize the battery lifetime on the anchor nodes. In order to show that battery powered infrastructure nodes are feasible, our solution accurately analyzes the long-term energy consumption of the infrastructure devices. Depending on the update rate and using a high capacity battery (10.4 Ah), it is possible to achieve a battery lifetime between 1 to 16 years, which is comparatively up to four times better compared to the current state-of-the-art TDMA-based solutions.